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From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Yibo Zhao <yiboz@codeaurora.org>, ath10k@lists.infradead.org
Cc: linux-wireless@vger.kernel.org, Yibo Zhao <yiboz@codeaurora.org>
Subject: Re: [PATCH V2 3/4] mac80211: fix low throughput in multi-clients situation
Date: Wed, 18 Sep 2019 11:59:28 +0200	[thread overview]
Message-ID: <874l19j56n.fsf@toke.dk> (raw)
In-Reply-To: <1568800033-17297-3-git-send-email-yiboz@codeaurora.org>

Yibo Zhao <yiboz@codeaurora.org> writes:

> Not long after the start of multi-clients test, not a single station is
> an eligible candidate for transmission since global virtual time(g_vt) is
> smaller than the virtual airtime(s_vt) of all the stations. As a result,
> the Tx has been blocked and throughput is quite low.
>
> This may mainly due to sync mechanism and accumulative deviation from the
> devision calculation of g_vt.
>
> For example:
> Suppose we have 50 clients in first round.
> Round 1:
> STA	weight	Tx_time_round  wt_sum	s_vt	g_vt  valid_for_next_Tx
> .	.	.			.		.
> .	.	.			.		.
> .	.	.			.		.
>
> After this round, all the stations are not valid for next transmission due
> to accumulative deviation.
>
> And if we add a new #51,
> Round 2:
> STA	weight	Tx_time_round	wt_sum  s_vt	g_vt  valid_for_next_Tx
> .	.	.			.		.
> .	.	.			.		.
> .	.	.			.		.
>
> Sync is done by:
> max(g_vt of last round - grace period, s_vt)
> and s_vt of #51 = max(2000 - 500, 0) + 1024 = 2524, and it is more than the
> final g_vt of this round.
>
> After this round, no more station is valid for transmission.

I'm not sure I understand this. Was there supposed to be numbers in
those tables above?

-Toke


  reply	other threads:[~2019-09-18  9:59 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-18  9:47 [PATCH V2 1/4] mac80211: Switch to a virtual time-based airtime scheduler Yibo Zhao
2019-09-18  9:47 ` [PATCH V2 2/4] mac80211: defer txqs removal from rbtree Yibo Zhao
2019-09-18  9:47 ` [PATCH V2 3/4] mac80211: fix low throughput in multi-clients situation Yibo Zhao
2019-09-18  9:59   ` Toke Høiland-Jørgensen [this message]
2019-09-18 10:29     ` Yibo Zhao
2019-09-18  9:47 ` [PATCH V2 4/4] mac80211: Sync airtime weight sum with per AC synced sta airtime weight together Yibo Zhao

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